Replace reflect.DeepEqual with cmp.Diff in tests

[tenzen-y]

/kind feature

Describe the solution you'd like
[A clear and concise description of what you want to happen.]
To improve visibility, we should replace reflect.DeepEqual with cmp.Diff in all test cases: https://github.com/kubeflow/katib/blob/master/docs/developer-guide.md#go-development

Here is an example for using cmp.Diff:

katib/pkg/apis/config/v1beta1/defaults_test.go

Lines 88 to 90 in 8df3c5c

	if diff := cmp.Diff(tc.wantConfig, kc.RuntimeConfig.SuggestionConfigs); len(diff) != 0 {
	t.Errorf("Unexpected SuggestionConfigs (-want,+got):\n%s", diff)
	}

Anything else you would like to add:
[Miscellaneous information that will assist in solving the issue.]

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[tenzen-y]

/good-first-issue

[google-oss-prow]

@tenzen-y:
This request has been marked as suitable for new contributors.

Please ensure the request meets the requirements listed here.

If this request no longer meets these requirements, the label can be removed
by commenting with the /remove-good-first-issue command.

In response to this:

/good-first-issue

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[tariq-hasan]

@tenzen-y I would like to take on this ticket.

[tenzen-y]

@tenzen-y I would like to take on this ticket.

Sure, Feel free to assign this yourself with "/assign" comment.

[tariq-hasan]

/assign

[Mu-Magdy]

Hi @tenzen-y

Is this issue solved or I can work on it?

[tenzen-y]

@tariq-hasan Are you still working on this?

[tariq-hasan]

I am working on it. I will open a new PR.

[github-actions]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[tenzen-y]

/remove-lifecycle stale